A Line Screen is the measure of how many halftone lines are printed in a linear inch. The value is expressed as Lines Per Inch (LPI), which usually seen in lithography, screen printing and more. This important measurement related to the way printers reproduce photographic images also defines the necessary resolution of an image. The LPI is dependent on the output device and the type of paper.

Common numbers of line screen measurement seen in sheet fed printing are 130, 150 and 450 (ProjectCenteroffers 450 line screen printing). The higher the number, the better the quality. People in the business of photography find this measurement to be very important to the quality of their work, as you can see here.